| The pallid sturgeon can be thought of as a living
dinosaur. The species belongs to a group of fishes that flourished about
70 million years ago during the Cretaceous period. The pallid sturgeon is a large fish; historic reports and photographs
document pallids at more than 80 pounds and six feet long. It has a
flattened, shovel-shaped snout and long tail. Bony plates cover the body.
Four dangling barbels hang in front of the toothless mouth. The pallid
sturgeon is listed as endangered on both the federal and state endangered
species list.
 Notwithstanding
its ancient roots, the species flourished in the Missouri River for
millennia, dependent upon the habitat diversity and constantly changing
environment of the "Big Muddy." With dam construction, most of this
habitat disappeared. Compounding the loss of habitat, river flow no longer
peaks in the spring, a cue thought to initiate spawning. Pallids may not
spawn successfully in the wild any more. A captive breeding program is
underway, whereby adults are brought to hatcheries to spawn, and young
pallids are then released. Recapture data indicates that survival of
released propagated pallids is good. However, the captive breeding program
has met an obstacle in a disease known as the shovelnose sturgeon
iridovirus, SSIV, that has been found at several hatcheries.
Pallid sturgeon females are thought to take 15 to 20 years to mature,
and males 7 to 9 years, so it will be some time before it is known whether
propagated pallids will reproduce successfully if appropriate river
conditions are available. Meanwhile, the population of adult pallid
sturgeon is dwindling, as adults die out with no upcoming generations to
replace them. If conditions do not change, pallids may be extinct by
2016.
It is illegal to catch pallid sturgeon today, and historical records
indicate that the pallid probably was not abundant in the recent past.
However, historical catch reports as late as the 1960’s suggest that
fishermen caught pallids fairly regularly in the pre-dam system. Angler
reports indicate that the pallid sturgeon was an excellent sportfish. The
species was also harvested for eggs, which were sold as caviar. If the
species recovers, it may again one day become a prime target for
anglers.
References:
USFWS. 1993. Pallid sturgeon recovery plan. U.S. Fish and Wildlife
Service, Bismarck, North Dakota. 55 pp.
USFWS Website. Accessed January 14, 2004. www.fws.gov.
USGS Website. Accessed January 14, 2004.
http://www.npwrc.usgs.gov/resource/distr/others/nddanger/species/scapalbu.htm
|
 |
